IEEE Electrification - December 2022 - 48

prediction for the interior zones of the simulated building
under summer conditions is more uncertain compared to
exterior zones. Also, note that the actual airflow rate
matches the predictions for both the interior and exterior
zones in the real building very well. This occurs because
there is not much demand flexibility during winter, and
the airflow is mostly at the minimum flow rate, which is
relatively easy to predict.
Figure 9(a) shows the WBE consumption without TCC
(green) and with TCC (blue) as well as the cleared electricity
price (black) for a summer day in the medium office
building. The high-price period is between 6 a.m. and
10 p.m., and the low-price period is the rest of the day. The
electricity prices are slightly higher midday than during
the early morning and late afternoon because electricity
transport losses are proportional to the square of electrical
current, which increases near midday. The actual consumption
(blue) with TCC is lower than the baseline (the
operation of the building without TCC or transactive markets,
i.e., business as usual) without TCC (green) when the
prices are high during the daytime, which results in
reduced electricity consumption when TCC is controlling
the VAV boxes. Because it is a summer day, the flexibility is
high in the building.
Figure 9(b) shows the actual WBE consumption (blue)
and the cleared electricity price (black) for a winter day
in the medium office 2 building. Because the building is
heated with hot water generated from a natural gas boiler,
there is negligible electric demand flexibility during
winter. The other HVAC systems also have limited flexibility
during heating operations because AHU supply
fans operate near minimum speeds when spaces
require heating.
Challenges and Lessons Learned From
Using Buildings as a Grid Asset
Buildings can be a significant asset to the grid because
they can support increasing the hosting capacity of distributed
renewable generation and electrification of the
built environment. However, to operationalize the deployment
of these grid services and realize the demand flexibility
in buildings, we need to overcome several challenges:
x More than 85% of commercial buildings and almost all
homes do not have proper control infrastructure to
enable building-grid integration. Therefore, there is a
need for low-cost control infrastructure.
x Most demand-response programs that utilities offer
are vertically integrated; i.e., they focus on controlling
a large number of similar devices, for example, connected
thermostats or connected electric water heaters.
Many of these programs are direct load control
programs with no ability for the customer to opt out.
This is not sustainable in the long run.
x Most building-grid integration efforts that coordinate
multiple DERs are one-off custom deployments. This
approach is neither cost-effective nor scalable. To
scale deployment, we need fully automated grid services
applications, and we need to accelerate the
deployment of these services.
x The decarbonization of electricity generation and
electrification of buildings by switching fossil fuelbased
heating equipment to electric HPs is a significant
step to mitigate climate change. However, it
could put a severe strain on the electric grid on a cold
winter morning. During this period, HPs will not have
enough heating capacity, so they will use backup
electric heat, which could create significant winter
37.5
40
0.05
0.045
32.5
35
27.5
30
22.5
25
20
Time
WBE Baseline
WBE Actual
Price
(a)
0.04
0.035
0.03
0.025
0.02
100
90
80
70
60
50
Time
WBE Actual
Price
(b)
Figure 9. (a) The simulated building electricity consumption with TCC (WBE actual) and without TCC (WBD baseline) and cleared electricity price
for the medium office building for one summer day. (b) The real physical building electricity consumption with TCC (WBE actual) and the cleared
electricity price of one winter day for the medium office 2 building. Consumption is shown on the left y-axis and price on the right y-axis.
48
IEEE Electrification Magazine / DECEMBER 2022
0.05
0.045
0.04
0.035
0.03
0.025
0.02
Average Hourly Demand (kW)
Price (US$/kWh)
Average Hourly Demand (kW)
Price (US$/kWh)
12 a.m.
3 a.m.
6 a.m.
9 a.m.
12 p.m.
3 p.m.
6 p.m.
9 p.m.
12 a.m.
12 a.m.
3 a.m.
6 a.m.
9 a.m.
12 p.m.
3 p.m.
6 p.m.
9 p.m.
12 a.m.

IEEE Electrification - December 2022

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